In the prior art it is common practice to include a low voltage inhibit circuit in microprocessor systems, for the purpose of preventing malfunction when a power voltage is low. The low voltage inhibit circuit is connected to the microprocessor power supply and sends a reset signal directly to the microprocessor whenever the voltage supplied by the power supply drops below a predetermined value.
The problems that arise with the above described structure is that data being transferred into a memory within the microprocessor can be interrupted at a midpoint in the transfer, resulting in erroneous data being stored in the memory. Further, it is often necessary to perform tests on the microprocessor circuits and system and it is desirable to allow continued operation at low voltage.